Elevating Tree Stand

ABSTRACT

A portable, elevating stand is constructed of a platform movably connected to a generally columnar upright support having a height along which movement of the platform is constrained. Connection between the platform and upright support may be through a linkage assembly comprising channels in which are positioned flange portions of the upright support, such flange portions being located along a majority of the height of the upright support. The platform assembly may be driven by a portable electric motor, including the use therefor of an hand-held electric drill, which is carried onto the platform assembly prior to use of the elevating stand. A method of raising and lowering a portable, elevating stand includes carrying onto the platform assembly a portable motor, engaging the motor with a means for raising or lowering the platform assembly, and operating the motor to effect raising or lowering of the platform assembly.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority to and the benefit of U.S. Provisional Patent Application Ser. No. 60/731,184 filed Oct. 28, 2005, the entire disclosure of which is herein incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a lift system for raising or lowering a platform. In particular, the apparatus provides a generally vertical beam against which a generally horizontal platform is constrained and along which the platform can move as the platform is raised or lowered by a winch or other means connected to the platform and having a cable running to near the top of the generally vertical beam.

2. Description of Related Art

Small, elevated, outdoor platforms that may be used for hunting or wildlife viewing are well known, in part because of their ease of construction and largely because of their great utility. Most often such a platform is built onto a tree, which provides the primary support therefor. A substantial disadvantage of such an elevated platform is that access is generally limited, most often being provided only by a ladder. Not uncommonly such ladder access is provided by only a primitive form of a ladder.

For hunters (or others wishing to use an elevated platform) who are not sufficiently agile, strong, steady, sturdy, or are otherwise of limited ability, a climb on a primitive ladder, or any ladder, may be daunting or impossible. For instance, persons with a physical disability or who are elderly may want to utilize such an elevated platform yet be unwilling or unable to climb to it. Even for persons willing and able to climb to an elevated platform, the climb may be dangerous. Injury from slips or falls while climbing a ladder is a well-known hazard. In fact, a professional analyst and commentator on the sport of hunting has suggested that as many as one-fifth of all hunters using ladders to access a stand will be injured.

SUMMARY OF THE INVENTION

The following is a summary of the invention in order to provide a basic understanding of some aspects of the invention. This summary is not intended to identify key/critical elements of the invention or to delineate the scope of the invention. Its sole purpose is to present some concepts of the invention in a simplified form as a prelude to the more detailed description that is presented later.

Instead of requiring a person to climb to an elevated platform, embodiments of the invention provide a lift system wherein the platform can be positioned low enough to the ground that a person can directly step or roll (as in the case of a person in a wheeled chair or other vehicle) onto or sit upon it, after which the platform, along with the person, can be raised into an elevated position.

In an embodiment, a portable, elevating stand comprises a generally columnar upright support having a height, the support including at least two flange portions projecting therefrom along at least a majority of the height; a platform assembly on which a user may stand or sit, the platform assembly being movably connected to the at least two flange portions of the support; and a means for raising and lowing the platform along the height of the column. In an embodiment, the at least two flange portions are comprised by a unitary plate portion mounted flush against a flat side of a tube portion of the generally columnar upright support. In an embodiment the tube portion has a square or rectangular cross section. In a further embodiment, the platform assembly includes at least two channels, each of the channels being sized and shaped to slidably engage at least one of the at least two flange portions; and wherein the channels are slidably engaged with the at least two flange portions, thereby constraining the platform assembly to move generally along the height of the column. In an embodiment, such a channel is constructed through the connection, in a stacked arrangement, of a main support plate, a spacer plate, and a flange keeper plate. In an embodiment, the generally columnar upright support comprises one of an I-beam, an angle iron, two angle irons attached back-to-back to form a shape generally described by a T, or a structure the shape of which is generally described by a double-T. In an embodiment, the stand further comprises a brake mechanism including one of a locking pin or a brake plate.

In an embodiment, the means for raising and lowering is a winch mounted on the platform assembly so as to be raised and lowered along with the platform assembly. In an alternate embodiment, the stand further comprises a hand-held electric drill connected to the winch through a gear set.

In a further alternate embodiment, a portable, elevating stand comprises an upright support having a height; a platform assembly on which a user may stand or sit, the platform assembly being movably connected to the upright support along the height thereof; a winch mounted on the platform assembly, the winch including a cable that traverses a distance from a drum of the winch to an attachment near a top of the support; and a hand-held electric drill operably engaged with the winch in a manner such that operation of the drill operates the winch and thereby effects at least one of the raising or lowering of the platform assembly along the height of the support. In an embodiment, the upright support comprises at least two flange portions projecting therefrom along at least a majority of the height; and the platform assembly is movably connected to the support only through connection to the at least two flange portions. In an embodiment, the support comprises a tube portion having a square or rectangular cross-section to which is attached flush against a flat side thereof a plate portion comprising the at least two flange portions, the shape of the support being that of a box-T.

An embodiment is a method of raising and lowering a portable, elevating stand comprising providing a portable, elevating stand that comprises a generally columnar upright support having a height; a platform assembly on which a user may stand or sit, the platform assembly being movably to the support; and a means for raising or lowing the platform along the height of the column; carrying a portable, electric motor and power source onto the platform; engaging the motor with the means for raising and lowering; and operating the motor engaged with the means for raising and lowering to effect raising or lowering of the platform. In an embodiment of such method the portable, electric motor is comprised by a hand-held drill, and the power source is a battery or fuel cell. In an alternate embodiment, the means for raising and lowering is a winch.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a plan view of an embodiment of a lift system.

FIG. 2 shows a perspective view of an embodiment of a linkage assembly

FIG. 3, including FIGS. 3A-B, shows cross sectional views of embodiments of upright supports having a generally box-T design, along with their engagement with a linkage assembly.

FIG. 4, including FIGS. 4A-D shows cross sectional views of embodiments of upright supports that do not include a hollow enclosed space, along with their engagement with a linkage assembly.

FIG. 5 shows alternate embodiments of a brake assembly, including a brake plate in FIG. 5A, a wedge in FIG. 5B, a pin in FIG. 5C, and a.cam in FIG. 5D.

DESCRIPTION OF PREFERRED EMBODIMENTS

As shown in FIG. 1, an embodiment of the portable, elevating tree stand comprises a seat 21, otherwise referred to as a sitting platform 21 for sitting upon, and a standing platform 23 connected thereto for standing upon or resting one's feet while sitting on the seat 21. Connected to the seat 21 and standing platform 23 is a winch 25. In this embodiment, the seat 21, the standing platform 23, and the winch 25 are part of the platform assembly 22, which is connected to a generally columnar upright support 27, along which the platform assembly 22 can move up and down. The platform assembly 22 is suspended above the ground by a cable 29 that is secured on one end to the winch 25 and on the other end to an attachment near the top of the upright support 27. Specifically as shown in FIG. 1, the cable of this embodiment is attached at the top of the upright support 27 to a generally horizontally projecting bar 31.

Configured as shown in FIG. 1, operation of the winch 25, which may be manual or automatic (for example operated by a hand crank or an electric motor, respectively) serves to raise and lower the platform assembly 22 as the cable 29 is respectively wound onto or unwound from the drum of the winch 25, thereby shortening or extending the length of the cable 29. Operation of the winch 25 allows the platform assembly 22 to be raised or lowered only to the point of reaching a stop 32 mounted on the upright support 27. In alternate embodiments the cable 29 is a multi-strand steel cable, a chain, or a rope. In a preferred embodiment, the cable 29 is a strap, such as a nylon webbing material, which is light weight and rolls onto the drum of the winch quietly. Throughout this disclosure the term cable is used as a generic term for any such specific embodiment of the cable 29.

Alternate embodiments of the portable, elevating tree stand include further convenience features on the platform assembly 22, such as a gun or shooting rail, a safety railing for preventing a user from falling off the platform assembly 22, or a sound deadening structure constructed about the winch 25.

In a preferred embodiment, the platform assembly 22 is slidably engaged with the upright support 27 via a linkage assembly 72, a particular embodiment of which is shown in perspective view in FIG. 2. As shown in FIG. 1, the linkage assembly 72 connects to the standing platform 23 via a support structure used to mount the winch 25. This support structure, which supports the winch 25 in the embodiment shown in FIG. 1, also is used in an embodiment for supporting a battery, for example, a 12 V battery as is used for a automobile or all-terrain vehicle, that provides the power to operate a motor driven winch.

In an embodiment, the winch 25 is a manually operated winch driven by a hand crank. In an alternate embodiment, the winch 25 is a motor driven winch. In an embodiment, a motor driven winch may be alternately manually driven, as, for instance, in the event of a motor failure. A motor driven winch will generally be driven by an electric motor powered by a battery as discussed above. In an alternate embodiment, the manual drive engagement socket of a winch 25 is driven by a portable electric motor carried onto the platform assembly 22 at the time of use. In a particular embodiment, the portable electric motor is comprised by a hand-held electric drill. In an embodiment, such a portable motor, whether or not embodied in a drill, is powered by a rechargeable battery, while in alternate embodiments, alternate power sources, such as a fuel cell, are used to power the portable motor. In an embodiment using a drill to drive the winch 25, the drill produces at least 400 inch-pounds of torque, and is connected to the winch 25 via a gear set that includes a worm gear to provide a 20:1 ratio between revolutions of the drill drive and the winch drive.

FIG. 3 illustrates, in a cross-sectional view from above, the connection between the linkage assembly 72 and the upright support 27 in a preferred embodiment. The cross-section of the upright support 27 shown in FIG. 3 indicates a box-T design for the upright support 27, formed by the components of the upright support 27, a square tube 77 and a unitary slide plate 79 rigidly attached thereto flush against a side of the square tube 77. In this embodiment, the extension of the slide plate 79 beyond the sides of the tube 77 forms flanges 81 on either of two sides of the upright support 27.

This preferred box-T design (FIG. 3) is particularly advantageous in that it is both strong and light weight. This box-T design allows the upright support 27 to readily support a significant amount of weight on the platform assembly 22 without significant deformation to the upright support 27, yet provides for a relatively small, relatively light weight and therefore relatively easily portable structure. The relatively small but strong box-T design allows the upright support 27 to take up relatively little volume, either when assembled and in use or when disassembled in stored. In a preferred embodiment of the box-T design, the square tube 77 is one and one half inches on a side, and the slide plate 79 is three inches wide, both constructed of steel and welded together.

Whereas the upright support 27 depicted in FIG. 3 comprises a tube of square cross section, in alternate embodiments the tube has a cross section of alternate shape, including other geometric shapes, such as being rectangular, triangular, circular, or oval, for example. Still other embodiments of the upright support 27 do not include a tube. Example cross sections are shown in FIG. 4 for alternate embodiments of the upright support 27 that do not comprise a tube. FIG. 4A shows two angle irons attached back-to-back to form a shape generally described by a T. FIG. 4B shows a structure generally described by a double-T (i.e., TT). FIG. 4C shows an I-beam structure. FIG. 4D shows an angle iron for the upright support 27. Each of these embodiments has in common the existence of flange portions 81 to which a linkage assembly can be connected. Each of these alternate structures provide the advantages of being relatively small, light weight, and strong, as well as providing the flanges needed for sliding engagement between the linkage assembly 72 and the upright support 27.

In the preferred embodiment shown in FIG. 3A, the linkage assembly 72 comprises a main support plate 71, which in an embodiment of the lift system is rigidly attached to the standing platform 23. The linkage assembly 72 also comprises spacer plates 73, and flange keeper plates 75. In this embodiment, the structure of the linkage assembly 72 is such that the flange portions 81 of the slide plate 79 of the box-T upright support 27 fits within a channel 78 of the linkage assembly 72 created between the flange keeper 75 and the main support plate 71 as a result of the spacer 73. Opposing faces of the flange keeper 75 and the main support plate 71 define the channel walls. This construction allows the linkage assembly 72 to be slidably engaged with the upright support 27, further allowing the linkage assembly 72 and the attached platform assembly 22 to slide vertically along the height of the upright support 27.

FIG. 3B shows an alternative embodiment in which the channels 78 of the linkage assembly 72 are formed by a single piece of material shaped to wrap around the flange portion 81 of the upright support 27, eliminating independent spacer plates 73 and flange keeper plates 75. The embodiments depicted in FIG. 4 also show this channel design. Regardless of the specific channel design, in preferred embodiments the channel is sized and shaped to allow in the range of about 1/100th of an inch to about 1/32nd of an inch of space between any channel wall and the flange portion 81 of the upright support 27 when the linkage assembly 72 is slidably engaged with the upright support 27. Also regardless of the specific channel design, in alternate embodiments, a coating of Teflon or other smooth, low-friction material is provided on the channel walls, or the faces of the flanges that interact with the channel walls during sliding, or both. In further alternate embodiments the linkage assembly 72 includes rollers that directly engage the slide plate 79 and allow rolling engagement rather than sliding engagement between the upright support 27 and the platform assembly 22.

A further component of the lift system depicted in FIG. 1 is a brake assembly. In this embodiment the brake assembly is designed to be operated by a force exerted on a brake pedal 19 by a user, who is sitting or standing on the platform assembly 22. Several alternate embodiments of the brake assembly are shown in FIG. 5.

In an embodiment shown in FIG. 5A, the brake assembly comprises a brake plate 125 having a flat surface positioned generally parallel and adjacent to, but biased by a spring 127 away from, the slide plate 79 of the upright support 27. The brake assembly in this embodiment is operated by a user, who is sitting or standing on the platform assembly 22, pushing on a brake pedal 19 that is connected to the brake plate 125 through a lever arm 20, thereby overcoming the biasing effect of the spring 127 and forcing the brake plate 125 against the slide plate 79. In this embodiment, frictional forces between touching surfaces of the brake plate 125 and the slide plate 79 are adjusted depending on the pressure a user applies to the brake pedal. In the event of a malfunction of the elevating mechanism (e.g., winch 25 and cable 29), the frictional forces between the brake plate 125 and slide plate 79 can be made, by pressure applied to the pedal 19, sufficient to slow or stop any decent of the platform assembly 22 due to gravity. This brake mechanism could also be used with the opposite bias, such that a user would have to apply a force (such as through a brake pedal) to overcome a biasing of the brake plate 125 against the slide plate 79 in order for the winch to readily raise the platform assembly 22.

Alternate embodiments of the brake assembly are depicted in FIGS. 5B-C. An alternate embodiment of the brake plate embodiment just discussed is depicted in FIG. 5B, which depicts an embodiment comprising a wedge 131, which, for instance, can be forced upwards from below into the channel 78 of the linkage assembly 72, for instance in the embodiment shown in FIG. 3A, between the main support plate 71 and the slide plate 79, thereby creating a frictional force among the linkage assembly 72, wedge 131 and slide plate 79 that opposes the downward pull of gravity and can slow or stop the downward movement of the platform assembly 22.

The brake embodiment of FIG. 5C is a pin assembly, which uses a spring 141 to bias the pin 143 either towards or away from the slide plate 79. In the embodiment of the lift system shown in FIG. 1, for instance, the brake assembly embodiment shown in FIG. 5C could be mounted on the main support plate 71. One method of use of this embodiment includes the engagement of the pin 143 with one of a plurality of holes in the slide plate 79. In such an embodiment, wherein the pin 143 is biased toward the slide plate 79, the user would apply a counter force to overcome the bias of the spring 141, such as by pulling on a release handle 145, thereby preventing the pin 143 from engaging a hole in the slide plate 79 and allowing the winch 25 to raise the platform assembly 22. In such an embodiment, when the release handle 145 is not engaged by a user, the platform assembly 22 can only move downward under the force of gravity until the pin 143 aligns with a hole in the slide plate 79, at which point the spring 141 will force the pin 143 to engage the hole, and the platform assembly 22 will be stopped.

A further alternate embodiment of the brake is shown in FIG. 5D, which is a cam assembly. This cam assembly brake operates in a similar manner to a mountain climber's ascender, allowing movement in one direction and halting movement in the opposite direction, though the mechanism has been adapted to the unique environment of the elevating tree stand, as discussed below. In an embodiment, as discussed below, this cam assembly brake is the preferred brake mechanism because it is completely automatic, not requiring any user intervention during elevation of the platform assembly 22, while maintaining contact with the upright support 27 and thereby operating instantaneously as a brake when upward movement of the platform assembly 22 halts.

As shown in FIG. 5D, in a preferred embodiment the cam 151 is mounted on a backing plate 159 to rotate about an axis 155 and is biased by a spring 127 to a position generally abutting against an upright support 27 (not shown). In an embodiment, the backing plate is rigidly attached to the platform assembly 22 in such a way that when the platform assembly 22 is connected to the upright support 27 as discussed above, a flange portion 81 is positioned between the cam 151 and the side plate 157. As the platform assembly 22 moves upwardly along the upright support 27, a generally downward frictional force is generated by the flange portion 81 on the cam 151, tending to rotate the cam 151 away from the upright support 22, and allowing the platform assembly to be elevated without binding the cam 151 and without user intervention. As the platform assembly moves downward, however, a generally upward frictional force is generated by the flange portion 81 on the cam 151, tending to rotate the cam 151 towards the upright support 27 and cause the cam 151 to bind against the upright support 27, thereby stopping the downward movement of the platform assembly 22. To allow downward movement of the platform assembly 22, the user must force the cam 151 to rotate against the bias of the spring 127, such as by creating a force that pulls downward on the cable 153, thus moving the cam 151 away from engagement with the upright support 27, and prohibiting the cam 151 from binding against the upright support 27. In other embodiments, the user may use any other mechanism known or later developed to rotate the cam 151 against the bias of the spring 127 in order to allow the platform assembly 22 to descend, including a lever directly attached to the cam 151.

In an embodiment, the upright support 27 is held in a generally vertical orientation by attaching the upright support 27 to a tree. In an embodiment, attachment to a tree is facilitated by stabilizers 33, which are rigidly attached to the upright support 27 and project in a generally horizontal direction that is generally opposite to the direction of projection of the bar 31 at the top of the upright support 27. In various embodiments, the stabilizers 33 have a shape generally defined by a V, including having an opening between two generally opposing surfaces or edges, which surfaces or edges define an angle. When the upright support is attached to a tree, the stabilizers 33 are mounted against the tree with the tree positioned in the opening between the opposing surfaces or edges, which contact the tree. In alternate embodiments, the stabilizers 33 have a generally curved configuration, generally like that of a U, wherein the surfaces or edges 35 are generally defined by arcs that fit about a portion of a tree's circumference, for instance. The commonality among embodiments of the stabilizers is projections which can be attached to an upright object, such as a tree, to provide enhanced stability to the upright support 27 when the upright support 27 is to be maintained in a upright position for use in supporting the generally vertical movement of a platform assembly 22.

Various methods of securely attaching a stabilizer 33 to the upright support 27 may be used, including welding. Additionally, various methods of connecting a stabilizer 33 to a vertical support, such as a tree, may also be used, including, for example, a rope, cable, chain, or strap connecting generally from one opposing surface or edge to the other opposing surface or edge of the same stabilizer 33 around a tree. In the preferred embodiment shown in FIG. 1, there are four stabilizers 33 along the height of the upright support 27. As shown in FIG. 1, stabilizers 33 may be placed vertically closer together near a joint in the upright support 27.

In alternate embodiments, the upright support 27 is held in a generally vertical orientation by other methods as are well known in the art, such as connection to other vertical structures, or as a free-standing upright support supported by outriggers or a base. Such embodiments are shown in U.S. Pat. No. 5,595,265, which is wholly incorporated herein by reference.

In an embodiment, the entire lift system is able to be sufficiently disassembled that the assembly components can be stored and transported in a storage compartment of a vehicle, such as the trunk of a standard passenger automobile, the bed of a pick-up truck, or the cargo area of a sport-utility vehicle. In an embodiment, this transportability is effected in part by the fact that the upright support 27 is constructed of at least two pieces. In a preferred embodiment, the upright support 27 is about sixteen feet in total height and is constructed of three pieces, one of which is about six feet in length and two of which are about five feet in length. The joints at which any two of the components of the upright support 27 fit together are constructed by any reasonable method known in the art that maintains the stability of the upright support 27 and the general continuity of the slide plate 79. The stability of the joint may be enhanced by the stability provided by the stabilizers 33, when the stabilizers 33 are used as described above and as shown in the figures. In an additional embodiment, a joint support 34 is included at the joint, as is shown to be located internal to the tube 77 in FIG. 1.

While the invention has been disclosed in conjunction with a description of certain embodiments, including those that are currently believed to be the preferred embodiments, the detailed description is intended to be illustrative and should not be understood to limit the scope of the present disclosure. As would be understood by one of ordinary skill in the art, embodiments other than those described in detail herein are encompassed by the present invention. Modifications and variations of the described embodiments may be made without departing from the spirit and scope of the invention. 

1. A portable, elevating stand comprising: a generally columnar upright support having a height, said support including at least two flange portions projecting therefrom along at least a majority of said height; a platform assembly on which a user may stand or sit, said platform assembly being movably connected to said at least two flange portions of said support; and a means for raising and lowing said platform along said height of said column.
 2. The portable, elevating stand of claim 1 wherein said at least two flange portions are comprised by a unitary plate portion mounted flush against a flat side of a tube portion of said generally columnar upright support.
 3. The portable, elevating stand of claim 2 wherein said platform assembly includes at least two channels, each of said channels being sized and shaped to slidably engage at least one of said at least two flange portions; and wherein said channels are slidably engaged with said at least two flange portions, thereby constraining said platform assembly to move generally along said height of said column.
 4. The portable, elevating stand of claim 3 wherein said channel is constructed through the connection, in a stacked arrangement, of a main support plate, a spacer plate, and a flange keeper plate.
 5. The portable, elevating stand of claim 2 wherein said tube portion has a square or rectangular cross section.
 6. The portable, elevating stand of claim 1 wherein said generally columnar upright support comprises one of an I-beam, an angle iron, two angle irons attached back-to-back to form a shape generally described by a T, or a structure the shape of which is generally described by a double-T.
 7. The portable, elevating stand of claim 1 wherein said means for raising and lowering is a winch mounted on said platform assembly so as to be raised and lowered along with said platform assembly.
 8. The portable, elevating stand of claim 7 further comprising a hand-held electric drill connected to said winch through a gear set.
 9. The portable, elevating stand of claim 1 further comprising a brake mechanism including one of a locking pin or a brake plate.
 10. The portable, elevating stand of claim 1 further comprising a brake mechanism including one of a wedge or a cam.
 11. The portable, elevating stand of claim 1 wherein said upright support is comprised of at least two components of generally similar structure that are joined at a joint.
 12. A portable, elevating stand comprising: an upright support having a height; a platform assembly on which a user may stand or sit, said platform assembly being movably connected to said upright support along said height thereof; a winch mounted on said platform assembly, said winch including a cable that traverses a distance from a drum of said winch to an attachment near a top of said support; and a hand-held electric drill operably engaged with said winch in a manner such that operation of said drill operates said winch and thereby effects at least one of the raising or lowering of said platform assembly along said height of said support.
 13. The portable, elevating stand of claim 12 wherein said upright support comprises at least two flange portions projecting therefrom along at least a majority of said height; and wherein said platform assembly is movably connected to said support only through connection to said at least two flange portions.
 14. The portable, elevating stand of claim 13 wherein said support comprises a tube portion having a square or rectangular cross-section to which is attached flush against a flat side thereof a plate portion comprising said at least two flange portions, the shape of said support being that of a box-T.
 15. A method of raising and lowering a portable, elevating stand comprising: providing a portable, elevating stand comprising a generally columnar upright support having a height; a platform assembly on which a user may stand or sit, said platform assembly being movably connected to said support; and a means for raising or lowing said platform along said height of said column; carrying a portable, electric motor and power source onto said platform; engaging said motor with said means for raising and lowering; and operating said motor engaged with said means for raising and lowering to effect raising or lowering of said platform.
 16. The method of claim 15 wherein said portable, electric motor is comprised by a hand-held drill, and wherein said power source is a battery or fuel cell.
 17. The method of claim 15 wherein said means for raising and lowering is a winch. 